iiinova — where your digital self keeps evolving

Chris Cook @zirkelc.dev · 28/07/2025

TIL you can use `@entity.Attributes.Lambda.Function` to group messages from multiple different log groups. Useful when you need to analyze cold starts from many Lambdas with a single cloudwatch query.

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Chris Cook @zirkelc.dev · 10/07/2025

Here's Lambdalet.AI - an AI-powered bookmarking and read-it-later service. It saves any page you're reading into your own Notion database — full text, fully searchable, zero fuss. I built this for the AWS Lambda Hackathon!

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Chris Cook @zirkelc.dev · 18/06/2025

If your using JSONata instead of JSONPath for your AWS Step Function workflow, here's how you can flatten an array of arrays:

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Chris Cook @zirkelc.dev · 11/06/2025

It would be nice if there was a way to pause Lambdas while waiting for a HTTP response. Like fire of a few requests, the Lambda goes into hibernate and automatically resumes when all requests have concluded.

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Chris Cook @zirkelc.dev · 09/06/2025

Using a reasoning model for coding feels like driving a sports car in stop-and-go traffic

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Chris Cook @zirkelc.dev · 27/05/2025

Long lived AWS IAM credentials for the management console would be nice

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Chris Cook @zirkelc.dev · 20/04/2025

In 2011, there was an proposal to change the type of null `typeof null === null` Too bad it didn't get accepted web.archive.org/web/20160331...

web.archive.org

harmony:typeof_null [ES Wiki]

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Chris Cook @zirkelc.dev · 18/03/2025

Found this TODO in my codebase 😄 If I make a PR, will @vitest.dev accept it? 👀

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Chris Cook @zirkelc.dev · 12/03/2025

I started a discussion for a new asymmetric matcher for @vitest.dev that checks if a property does not exist. Basically, the opposite of `expect.anything()`, could be named `expect.nothing()` Would love to get some feedback 🙏 github.com/vitest-dev/v...

github.com

Asymmetric matcher for property NOT exists (opposite of `anything`) · vitest-dev vitest · Discussion #7324

Hey, is there a way check if an object does not have a certain property? Basically, the opposite of expect.anything(): import { expect, test } from 'vitest' test('object has "apples" key', () => { ...

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Chris Cook @zirkelc.dev · 02/02/2025

TIL `$*` captures all positional arguments into a space separated string You can abuse this for a Git alias to avoid typing the commit message in double quotes: `gc my commit message`

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Chris Cook @zirkelc.dev · 31/01/2025

I can't emphasize enough how great this post about quantization is!

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Chris Cook @zirkelc.dev · 29/01/2025

It's funny, @sindresorhus.bsky.social has a package for literally everything I search for. I should probably prefix my Google searches with "site:github.com/sindresorhus/"

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Chris Cook @zirkelc.dev · 27/01/2025

Building and deploying a React app to a static hosting service like Amazon S3 and CloudFront is a good example for a CLI in TypeScript. Adding Listr2 and Execa to create an easily extensible CLI with `build` and `deploy` command. asciinema.org/a/DFlVSxmoWD...

asciinema.org

untitled

Recorded by zirkelc

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Chris Cook @zirkelc.dev · 24/01/2025

It's so funny how confident LLMs are when they make mistakes. The model generates invalid code. You specifically ask them about lines of code. The model confidently explains how it works. You give them the error. The model is like "Ah, you're absolutely right - I apologize for my mistake!"

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Chris Cook @zirkelc.dev · 23/01/2025

What if `expect(obj).toMatchPrompt("...")` was a thing It's probably a stupid idea, but I couldn't resist and quickly implemented @vitest.dev custom matcher

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Chris Cook @zirkelc.dev · 20/01/2025

I wish VSCode would accept S3 URLs Cmd+P, paste S3 URL, enter and it opens the file

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Chris Cook @zirkelc.dev · 18/01/2025

I love how you can use TypeScripts' unique symbols as a parking spot for types 👀 Here's a simple query helper function to attach the result type to an object and infer it back later I've shared a complete example on @dev.to: dev.to/zirkelc/uniq...

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Chris Cook @zirkelc.dev · 16/01/2025

I noticed that Vercels' popular `ms` pkg for converting time units to milliseconds uses 365.25 as a multiplier for the days in a year. I know this is to account for leap years, but is that the right assumption to make here? Effectively this means that `ms(1y) != ms(365d)` without ppl knowing it

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Chris Cook @zirkelc.dev · 15/01/2025

Here's @tkdodo.eu original post where I saw this pattern for the first time. It's also the first time that using TypeScripts' `unqiue symbol` has made any sense to me. tkdodo.eu/blog/the-que...

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Chris Cook @zirkelc.dev · 15/01/2025

Inspired by React Query's `queryOptions()`, I made a little helper to add the type of the parameter and the return type to the query definition (yes, I know about ORM). The next step would be to use template literal types to parse the parameters and return type from the query string.

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Chris Cook @zirkelc.dev · 15/01/2025

I just stumbled upon `unbuild` from @unjs.io Bundling for ESM and CJS is already super easy thanks to `tsup`, but `unbuild` looks even nicer! github.com/unjs/unbuild

github.com

GitHub - unjs/unbuild: 📦 A unified JavaScript build system

📦 A unified JavaScript build system. Contribute to unjs/unbuild development by creating an account on GitHub.

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Chris Cook @zirkelc.dev · 13/01/2025

Some packages like Chalk by @sindresorhus.bsky.social are so popular that you can literally run for years without issues before you notice that you missed to declare it as dependency.

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Chris Cook @zirkelc.dev · 13/01/2025

I think I've finally found an efficient way to use LLMs for writing articles: 0. Draft article 1. Ask LLM to check the logic: does it make sense? No text changes 2. Ask LLM to fix spelling and grammar. No rewrites, only proofreading 3. Ask LLM to rewrite the text. Keep ideas, express them better

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Chris Cook @zirkelc.dev · 12/01/2025

I released `aws-sigv4-sign` today. It contains the core logic for signing requests with AWS SigV4, but does not use the fetch API The question now is: if you use fetch, then use `aws-sigv4-fetch`. In all other cases (axios, got, ky, node:https...) use `aws-sigv4-sign` www.npmjs.com/package/aws-...

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Chris Cook @zirkelc.dev · 10/01/2025

@arethetypeswrong doesn't support @pnpm.io `publishConfig` to override package.json export fields when using live types As workaround, we can run pnpm pack, extract the tarball name and pass it to @arethetypeswrong to check the types: `pnpm pack | tail -n1 | xargs attw` github.com/arethetypesw...

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Chris Cook @zirkelc.dev · 10/01/2025

I use jest-dynalite to run DynamoDB locally to avoid mocking database calls. It's so fast that I can create the necessary items before each test and reset the whole database between test. It's really good! Btw, despite the name, it works with well @vitest.dev github.com/freshollie/j...

github.com

GitHub - freshollie/jest-dynalite: Jest preset to run Dynalite (DynamoDB local) per test runner

Jest preset to run Dynalite (DynamoDB local) per test runner - freshollie/jest-dynalite

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Chris Cook @zirkelc.dev · 07/01/2025

It's crazy to think how different the experience must be for someone starting out in programming today vs. 15 years ago due to remote work and AI. When I started working in 2009, I learned so much by just sitting next to a person and watching them program.

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Reposted by Chris Cook

Thorsten Ball @thorstenball.com · 07/01/2025

In case you didn't know: In GitHub-flavored Markdown you can use <kbd> to specify keyboard input. Makes your shortcuts look ✨pretty✨

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Chris Cook @zirkelc.dev · 05/01/2025

Ordinal dates with year-dayOfYear (YYYY-DDD) even have an ISO standard. And the math is so simple, because days are absolute (24*60*60 s) whereas months are relative (28/30/31 d). Basically you only need to know if the year has 365 or 366 days. en.wikipedia.org/wiki/Ordinal...

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Chris Cook @zirkelc.dev · 05/01/2025

Date and time is a fascinating topic. You basically only simple arithmetic (plus, minus, multiply, divide) to manipulate a millisecond value. It's weird how we've made it more complicated with calendars and timezones. Using ordinal numbers (day of the year) would simplify so much.

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Chris Cook @zirkelc.dev · 04/01/2025

TypeScript Function Overloading I used to overload functions where I merge the different parameter names and types into one implementation signature like `startOrLength`. But it get's really messy with more than 2 params. The usage of rest args offers a really nice alternative. /

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Chris Cook @zirkelc.dev · 02/01/2025

TIL: Vitest has a built-in option to suppress logs during tests. I usually spy on the logger/console object and mock the implementation to disable logging during tests. It turns out Vitest has `onConsoleLog` option to filter or even suppress logs. vitest.dev/config/#onco...

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Chris Cook @zirkelc.dev · 30/12/2024

Finally closing a long standing issue with AWS SigV4 fetch and Node.js `Request` object and it was quite simple: I didn't copy the `duplex` property to the signed request, which caused a `TypeError` in certain cases 🫣 Luckily, someone pointed my in the right direction github.com/zirkelc/aws-...

github.com

Non-GET requests don't work when passed as a single Request argument · Issue #19 · zirkelc/aws-sigv4-fetch

When passing a non-GET Request object as a single argument, the method is automatically changed to "GET".

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Chris Cook @zirkelc.dev · 27/12/2024

Wild that you can implement merge sort as type in TypeScript github.com/saiashirwad/...

github.com

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Chris Cook @zirkelc.dev · 26/12/2024

My Wife: „what are you reading about?“ Me: „how to scale a website with a million checkboxes“ 👀

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Chris Cook @zirkelc.dev · 23/12/2024

Looking forward to Vitest v3. I made my first contribution with a new matcher `expect.toBeOneOf()` to check for optional properties that can be undefined or null. main.vitest.dev/api/expect.h...

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Chris Cook @zirkelc.dev · 23/12/2024

I really like the JS-DevTools/npm-publish action for publishing npm packages from a GitHub workflow. Just increment the package version and push it to GitHub and it will do the rest. github.com/JS-DevTools/...

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Chris Cook @zirkelc.dev · 19/12/2024

@pkg.pr.new is great for testing PRs of your own forks live. I am working on a PR for the serverles-step-functions plugin to support JSONata. Since I'm not the repo owner, I can't publish a beta version to test it in my app. I could use npm link, but that only works locally.

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Chris Cook @zirkelc.dev · 18/12/2024

I updated my snapshot plugin for Jest and Vitest Now you can replace or remove multiple properties at once using arrays or regex patterns in your snapshots. Perfect for handling dynamic values like auto-generated IDs or timestamps github.com/zirkelc/snap...

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